Just hours before the start of the 2026 FIFA World Cup, the continent's health authorities face a growing concern: the spread of measles in the Americas and the risk that the arrival of millions of international travelers will favor the further spread of the disease.

In an epidemiological alert issued on May 29, the Pan American Health Organization (PAHO) recommends that countries in the region review the performance of their measles and rubella surveillance systems, as well as vaccination coverage, to identify areas at highest risk and implement preventive actions.

The warning arises in a context of sustained increase in cases both in America and in other regions of the world. According to PAHO, the increase in international mobility associated with the World Cup and other massive events could facilitate the transmission of the virus, especially among people who do not have complete vaccination schedules.

“Countries must increase the sensitivity of their surveillance systems by actively searching for cases and ensuring vaccination information and services for travelers,” the organization said in a statement.

Recommendations for travelers and health authorities

Among the main measures suggested by PAHO is preventive vaccination of people over six months of age who cannot demonstrate having received two doses of the measles vaccine or who do not have evidence of immunity.

The recommendation is that immunization is preferably applied at least two weeks before travel to allow adequate protection. In addition, health authorities will have to provide information on the symptoms of the disease, which include high fever, skin rashes, cough, runny nose, conjunctivitis and swollen glands.

PAHO also asked that any traveler who presents compatible symptoms while traveling seek immediate medical attention, wear a mask, limit contact with other people and avoid going to public places until receiving a professional evaluation.

Upon returning to their places of origin, travelers who suspect they have contracted the disease should inform health services about their recent movements to facilitate early detection of possible chains of transmission.

Cases increase in America

The health alert coincides with a sharp increase in infections on the continent. According to PAHO data, between epidemiological weeks 1 and 20 of 2026, more than 20,000 cases of measles and dozens of deaths were confirmed in the region.

The figure represents a four-fold increase compared to the same period in 2025 and already exceeds the total number of cases recorded throughout last year.

Mexico concentrates the largest number of reported infections, followed by Guatemala. Outbreaks and cases associated with imports have also been identified in countries such as Canada, the United States, Peru, Bolivia, Belize, Costa Rica, El Salvador, Honduras, Panama and Uruguay.

In the United States, the Centers for Disease Control and Prevention has reported nearly 2,000 cases so far this year, reflecting a trend that worries public health authorities.

PAHO highlighted that the majority of confirmed infections have occurred among unvaccinated people or people with unknown immunization history.

Although a measles vaccination certificate is not an international entry requirement under the International Health Regulations, the organization reiterated that vaccination continues to be the most effective tool to prevent infections and avoid outbreaks during global events such as the 2026 FIFA World Cup.

With millions of fans expected in the United States, Mexico and Canada in the coming weeks, health authorities seek to prevent the football festival from coinciding with a new regional expansion of a disease considered preventable by vaccination, and although a vaccination certificate is not a mandatory entry requirement under international standards, authorities remember that immunization is the only real defense to protect communities.